Thread-cutting device.



1. G. GREENE & L. F. A. BU'CHNER.

IHREAD CUTTING DEVICE.

APPLICATION FILE-:1 MAILIB, 1912.

1,208,949. Patented Dec. 19,1916.

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1. a. GREENE & L. F. :A; BiJ'cHNER.

THREAD GUTTING DEVICE.

APPLICATION FILED ILL 15. ISIZ. I

' Patented D60. 19, 1916.

3 SHEETS-SHEET 2.

1.11. GREENE 1 L. F. A. BUCHNER. THREAD CUTTING DEVICE.

APPLICATION FILED MAR.1G. I912. 1,208,949. Patented Dec. 19,1916.

3 SHEETS SHEET 3.

WITNESSES: I I IVE/{TORS 7 26W $1M M 49d 5 A TTOHNEY To all whom it may concern Beitknown that we, JAMES G. GREENE and LOUIS F. A. Bt'cHNEn, citizens of the l 'nited States, residing at Elizabeth, in the county of Union and State of New Jersey,

provements in .lhread-(lutting Devices, of

cure being had therein to the accompanying 1o drawings.

i This invention relates to an improvement sewing machines at the completion of a stitching operation, and particularly in but- 5 tonhole stitching machines in which the cut- 1. ting of the slit occurs after a stitching operution, although certain of its features are applicable to other types of machines.

l The invention has for its object to proide thread-cutting mechanismin which the from stitching position, but are adapted to advancefor a cutting operation into'cl'ose ,l'iroximity with the stitch-forming mechaanism-andthework and to thereafter hold "the cut end of'the thread advantageously for productionof the initial stitch ofla suc ceeding stitching operation.

ting-blades by means of a pair of links which" the carrying member derivesmo've v dition to its endwise movements.

ting and 'nipping elements are retracted 10 brace the thread leading from' the needle thereof leading to the needle. r

As applied to the buttonholestitchingand cutting machine formingthe subject of ur applications Serial No. 576,639,,filed 11, 19-10.; and Serial No. 597,113, filed D 13, 191.0,the upper cutting blade'a p ping jaw are mounted upon :rspring-press "d lever fulcrmned 'upon the carrier. slit-h lever Specification of Letters Patent.

have invented certain new and useful 'Imwhich the following is a specification, referin means for cutting the'upper thread in cut-ting members are normally retracted larger scale representing the thread cutting mechanism from the front of the machine In the preferred embodiment of the improvement, the cutter-carrying member is suspended fol-movement endwise of the out senting the operation upon the needlemounted upon'fulcra disposed transversely 'ofthe fulcrl'un of a rocking frame from: A

chine is constructed with a frame comprisments crosswise of its cutting blades.in ad- The'car rieris' normally so positioned that its eutl from and in front of the needle-path,- in performing a cutting action are first moved rearward of the needlepath and then. advanced to enable such elementsto emeve as the work in which position they are closedto sever the thread and n1p the end v0 having a shoulder adapted in the-advance UNITED-STATES PATENT OFFICE. v

JAMES G. GREENE AND LOUIS F. 'L- B'UCHNEB, 0F ELIZABETH, JERSEY, ASSIGN- OBS TO THE SINGER MANUFACTURING COMPANY, A CORPORATION OF NEW JERSEY.

THREAD-CUTTING DEVICE.

Patented Dec. 19, 1916.

Application filed March 16, 1912. Serial No. 684,124.

In the drawings, Figure 1 is a perspective view of the entire machine, and Fig. 2 a similar view of the forward portion of the same abovethe work-plate with the thread cutting mechanism in a different stage of its operation from that of the previous figure.

. Fig. 3 represents a detail of the slit-cutting mechanism from which the thread-cutting mechanism derives lts operative movements. Figs. 4: and 5 are perspective views upon a vation, of the opposite side from that of A Fig. 6, of the carrier and the thread-cutting and nipping members sustained thereby, and

'Figs. 9 and ,10 front end elevations of the same parts in different positions and reprethread- Asrepresented in the drawings, the maing the. bed-plate 1 from which rises the lower base-member 2 supporting the fixed work-plate 3, the standard and overhang- Ring arm 5 constituting the upper frame member,wl1ich lattenwith the standard 4,

isstrengthenedby therib 6 extending from the rear of the bed-plate upwardly andforwarglly to the upper boss 7 affording one of bearings for the rotary needle-barb'usb ings, the other of which is journaled in the lower bearing boss 8. Journaled in suitable hearings in the standard 4 is the, transverse Iain or driving shaft carrying theloose looper mechanism mounted upon the rotary ving-pulley-9 from 'which'it derives, its ative movements through a suitable, e1 teh device. 1 f

he= ma1n-shaft is. connected by suitable carrier 12 beneath the work-plate and deriving its operative movements also from a connection with the main-shaft. Traveling movements are imparted by means of suit able actuating mechanism connected'with the main-shaft through the connecting bar 13 to the work-holder slide-plate 14 from which rise the bearing lugs 15 sustaining the operating rock-shaft 16 and provided with the backwardly ofi'set extensions 17 which in practice afl'ord fulcrum supports for the spring arms 18 carrying the clamping feet 19 between which and the plates 20, affording the lower clamping jaws, the fabric f is clamped for a button-hole stitching and cutting operation. An operative connection is provided in practice between the rockshaft 16 and the clamp-arms 18 whereby the latter are depressed and lifted in clamping and releasing the work.

As represented in the drawings, the slitcutting mechanism comprises, 1n conjunction with a lower cutting member, a cutter-block 21 secured upon the outer end of an arched supporting lever 22 which is fulcrumed upon a transverse rock-shaft concentric with the stud-screw 23 tapped therein and provided with a depending arm 24 having operative connections with the lower cutting member whereby the latter is shifted into and out of register with the upper-cutter member preparatory to and succeeding a slit-cutting operation.

The cutter-supporting lever 22 is connec ed by means of the pix'otal pin 25 with a link 26 constituting one member of a toggle and connected by thepin 27 with another link 28 constituting the other toggle member which is fixed upon the rocking fulcrum-pin 29 journaled in the frame member 5. The pin 27 affords a pivotal connection between the two links 26 and 28 of the toggle and the forward end of the pitman-bar 30 whose apertured opposite end embraces the crankpin 31 carried by a segmental plate 32 secured to the forward face of an actuating worm-wheel 33 which is mounted upon the supporting stud 34and adapted to be thrown into operative relation with the worm 35 upon the upright worm-shaft 36 which is driven from below the bed-plate 1 by suitable means. Means are provided for maintaining the worm-wheel 33 normally out ofmesh with the worm 35 but for placing the same in operative relation therewith at the completion of a button-hole stitching opera tion to receive therefrom a single rotation for actuation of theslit-cutting mechanism.

Mounted in a depending lug 37 of the lower bearing boss 8 of the bracket-arm is afulcrum-pin 38 upon which is confined by means of the collar 39 the hub 40 of a. rocking frame composed of the upwardly extending arm 41, provided with the cam-slot 42, and the depending arm 43 formed at opposite ends with the bearing bosses 44 and 45 spaced apart longitudinally of the hub 40 with the boss 45 depending therefrom lower than the boss 44, so that their apertures are in a plane downwardly inclined toward the needle-path relatively to the hub 40 which is disposed in transverse relation to the latter.

Mounted in the bearing bosses 44 and 45 are the pivotal pins 46 and 47 from which depend the parallel links 48 and 49 whose apertured lower ends embrace the studs 50 and 51 projecting laterally from the cuttercarrying bar 52. As the links 48 and 45) are of substantially the same length, it will be .observed that they, with the rocking frame arm 43 and carrier 52, constitute a parallel motion with the latter member inclined downwardly toward the work-plate.

Fixed upon the rocking fulcrum-pin 29 is a forwardly and downwardly extending arm 53 carrying a roller-stud 54 entering the cam-slot 42 of the rocking frame arm 41 and normally disposed within the lower angularly arranged portion 42 of said slot, the upper portion of which is in practice curved concentrically with the fulcrum-pin 29, as indicated more particularly in Fig. 2. As the upper-cutter lever 22 begins to descend for a slit-cutting operation in the straightening of the toggle 26 28 by advance of the pitman-bar 30, the swinging of the arm 53 causes its roller-stud 54 to first traverse the angular portion 42 of the camslot 42, whereby the rocking frame 40, 41, 43, is oscillated upon its fulcrum-pin 38 to shift the carrier 52 from a position in front of to one rearward of the needle-path preparatory to advance of the same for a threadengaging action, after which the traverse of the concentric portion of the cam-slot by the roller-stud 54 serves to maintain the rocking frame stationary during the remainder of the slit-cutting operation.

The cutter-supporting lever 22 ca-rrie near its forward end a lateral stud-pin 55 which, as the lever descends, enters an openended slot 56 of a lateral cam-arm 57 rigidly connected to and in angular relation with the link 49 forming one of the swinging supports of the carrier 52. As the lever 22continues to descend, the engagement of the stud-pin 55 with the lower side of the slot 56 serves to turn the crank-arm 57 downwardly about the pivotal pin 47 as a fulcrum, thereby imparting through the link 49 an endwise advance movement to the carrier 52 to bring its cutting and nipping members into operative relation with the stitch-forming and work-holding devices and into engagement with the needle-thread leading from one to the other. This operation of the stud-pin 55 is performed in opposition to the action of a spring 58 having one end secured by means link 49, and its other end attached by the screw 60 to the frame member 5, and acting through-the link 49 to maintain the carrier 52 yieldingly in upper and retracted position.

The offset forward end portion of the carrier 52 has secured within a seat formed in the back of the same by means of the screw 61 the shank 62 of a thread-cutting blade 63 which coeperates in practice with a cutting blade 64 formed upon the adjacent edge at the forward end of the cutter-lever 65 which is fulcrumed by means of the studpin 66 passing through a. transverse aperture in the carrier 52 and surrounded by a spring 67 interposed between the head of the screw 66 and the carrier by means of which the cutter-lever is pressed yieldingly against the adjacent operative face of the carrier and in cutting relation with the cutting blade 62.

Secured upon the forward face of the carrier 52 by means of the fastening screw 68 is the shank 69 of the lower nipping blade 70 whose nipping face is disposed in operative relation with that of the upper nipping blade 71 whose shank 72 is secured by means of the screw 73 upon the adjacent face of the cutter-lever 65. The cutter-lever, is maintained normally in its lower operative position with its upper cutting and nipping elements closed with their respective coiiperating elements by means of a spring 74: having a hooked extremity 75 resting upon the upper edge of the cutter-lever, its opposite end resting upon the shank of a stud-screw 76 tapped into the stud 50, and its intermediate portion resting against the lower. side of the stud-screw 77 carried by the cutter-lever and serving as a stop for the edge of a notch 7 8 in the cutter-lever 65.

The forward extremity of the, cutter-lever affords a shoulder in the form of a lateral stud 7 9 for engagement with the inclined lip 80 of a cam-block 81 fulcrumed upon a pin 82 which is mounted in the bearing lugs 83 carried by one of the clamping feet 19. The pin 82 is embraced intermediate the bearing lugs 83 by a, coiled sprlng 84L havm one end anchored in the bearmg lug an provided at the other end with an arm 84* resting upon the top of the cam-block 81 and serving to maintain the same yieldlngly seated upon the top of the foot 19, as represented in Figs. 4 and 5. The parts are so arranged and operated that in the advance of the carrier 52 for action upon the needlethread, the stud 79. rides up the inclinedupper face of the lip 80 of the cam-block and the cutter-lever 65 is thereby lifted in opposition to its spring 74L to separate the cutting and nippin elements for reception of the needle-three as represented in Figs. 6 and 9, and at the end of its advance movement the stud 79 rides off the end of the of a fastening screw 59 to one edge of the cam-lip 80 to enable the spring 74 to close the upper cutting and nipping elements upon the lower coiiperating element, thereby cutting and nipping the thread,- as represented in Fig. 10. In the subsequent retractive movement of the carrier 52, the stud 7 9 engages the lower face of the cam-lip 80 and lifts the cam-block in opposition to its spring 84, thereby insuring against injurious interference of the parts in the return of the cutting mechanism to initial position.

In buttonhole sewing machines as usually constructed, at the completion of a stitching operation, the lead of the upper thread between the needleeye and the work is substantially vertical, but in the machine represented in the accompanying drawings and disclosed in detail in our applications before mentioned,"and also in an application filed simultaneously herewith, Serial No. 685,490, the Work-clamp is retracted for the slit-cutting operation by a connection of a section of the link 13 with the slit-cutting mecha nism, thus bringing the lead of the thread it in a backwardly inclined direction substantially as represented in Fig. 9. It is evident, however, that this shifting of the workclamp for the slit-cutting operation is not essential to the present invention, although it provides an advantageous positioning of the thread for introduction between the thread-cutting and nipping elements.

In the operation of the machine as herein shown and described. the stitching operation immediately follows the closing of the workclamp upon the fabric, the initial thread end a being maintained nipped between the upper and lower nipping jaws 71 and 7 0. as represented in Fig. 4, in such manner that the lead of this branch of the thread is forwardly of the needle path and upon the side thereof from which the thread issues from the needle-eye, thereby insuring against the twisting of the initial thread-loop presented for the loop'taker and avoiding the skipping of the initial stitch. At the completion of the second side stitching operation, the stitch-forming mechanism is arrested and the slit-cutting mechanism operated to form the slit intermediate the spaced overseams composing the sides of the buttonho-le. the work-holder being at the same time retracted to bring the stitched and still uncut buttonho-le into register with the slit-cutting members. Simultaneously with the operation of the slit-cutting mechanism, the thread-cutting action takes place by means of its operative connection therewith, as before de scribed, the carrier 52 advancing toward the thread-severingmechanism mounted separately from and connected with and controlled in the timing of its action by said slit-cutting mechanism.

2. In a buttonhole stitching machine, the combination with stitch-forming mechanism, of slit-cutting mechanism, thread-severing mechanism independent of the latter, and means for simultaneously actuating said slitcutting and thread-severing mechanisms.

3. In a buttonhole stitching machine, the combination with stitch-forming mechanism, of slit-cutting mechanism, thread-severing mechanism independent of the latter, and common actuating means for said slit-cutting and thread-severing mechanisms.

'l'. In a butt-onhole stitching machine, the combination with stitch-forming mechanism, and slit-cutting mechanism, of distinct thread-severing mechanism mounted separably from and having an operative connection with said slit-cutting mechanism and deriving its operative movements through said connection.

In a buttonhole stitching machine, the combination With stitch-forming mechanism, of a thread-severing device including separable cutting elements, means for bodily moving said thread-severing device into and out of thread-severing position, and including a movable actuating member connected with and adapted to impart the initial movement to the severing device. and a second movable actuating member initially disconnected from the severing device but adapted to assume operative relation with the latter after'the action of theinitially connected member and impart a subsequent bodily movement to said severing device in a direction at an angle to the direction of the initial movement, and means for opening and closing said cutting elements.

(3. In a buttonhole stitching machine, the combination with stitch-forming mechanism, a work-holder, and slit-cutting mechanism, of a thread-severing device including separable cutting elements, means connected with and actuated by said slit-cuttingmechanism for moving said thread-severing device into and out of operative relation with the thread held by said stitch-forming mechanism, and means carried by the Work-holder for controlling the opening and closing of said cutting elements to admit and sever the thread.

pivoted supporting elements for said carrier,

means for bodily moving both of said supporting elements to move the carrier laterally from a. retracted position at one side of the needle path, and means for moving said supporting elements about their pivots to impart an endivise movement to the carrier to bring its cutting and nipping elements to the opposite side of the needle path and into operative engagement with the thread leading from the needle-eye.

8. In a buttonhole stitching machine, the combination With stitch-forming mechanism including a reciprocating needle, of a. thread-severing and nipping device com prising a carrier movable in difiierent directions in angular relation each with the other and sustaining pairs oi separable cutting and nipping elements, of means for maintaining said carrier normally retracted With its cutting and nipping elements at one side of the needle-path for holding the threadend for the initial stitch of a group, and means including separate members acting independently and alternately upon the carrier for laterally shifting and advancing said carrier to bring its cutting and nipping elements into operative position at the opposite side of the needle-path for a threadsevering and nipping action.

9. In a buttonhole stitching machine, the combination with stitch-forming mechanism including a reciprocating needle, of a thread-severing device comprising a carrier, cooperating cutting elements sustained by said carrier at one side of the needle path and out of line With the needle, shifting means connected with said carrier for moving the cutting elements to the opposite side of the needle, means acting positively and independently of said shifting means for moving said cutting elements into operative position adjacent the needle, and means distinct from said positively acting means for closing said cutting elements to sever the thread.

10. In. a buttonho le stitching machine, the combination with stitch-forming mechanism including a'reciprocating needle, of a tl'n'ead-severing,device comprising a carrier, cooperating 'cutting and nipping elements sustained by said carrier at one side of the needle path'and'out of line with the needle, shifting means connected with said carrier from moving the cutting elements from initial positio'n'to a position at the opposite side of the needle, means connected with said carrier and movable differentially with respect'to said shifting means for moving endwise each of said cutting elements into operative engagement with the thread atsaid opposite side of the needle, means for closing said cutting elements to sever the thread and means for returning said carrier to initial position.

11. In a buttonhole stitching machine, the combination with stitch-forming mechanism including a reciprocating needle, of a thread-severing and nipping device comprising a rocking frame, a fulcrum therefor arranged transversely to the needle-path, a carrier sustained by said rocking frame and movable thereon in substantially the plane of said fulcrum, pairs of separable cutting and nipping elements mounted upon said carrier and sustained normally at one side of and retracted from the needle-path, and actuating means including independent connections with said rocking frame and said carrier whereby said frame is-rocked to direct the carrier to the opposite side of the needle-path and the carrier is advanced for engagement of its cutting and nipping elements with the, thread leading from the needle-eye.

12. In a buttonhole stitchingmachine, the combination with stitch-forming mechanism including a reciprocating needle, of a thread-severing and nipping device comprising a rocking frame, a fulcrum therefor arranged transversely to the needle-path, a pair -of links suspended from said rocking frame by pivotal connections disposed trans versely to said fulcrum, a carrier pivotally connected at different points with said links, pairs of separable cutting and nipping ele ments mounted.upon said carrier and sustained normally at one side of and retracted from the needle-path, and actuating means including independent connections with said rocking frame and said carrier whereby said frame is rocked to direct the carrier to the opposite side of the needle-path and the'carrier is advanced for engagement of its cutting and nipping elements with the thread leading from the needle-eye.

13. In a buttonhole stitching machine, the combination with stitch-forming mechanism including a reciprocatin needle, and'slitcutting mechanism, of a t read-severing and nipping device comprising a rocking frame, a fulcrum therefor arranged transversely to the needle-path, a carrier sustained by said rocking frame and movable thereon in substantially the plane of said fulcrum, pairs of separable cutting and nipping elements mounted upon said carrier and sustained normally at one side of and retracted from the needle-path, and actuating means including independent connections between the slitcutting mechanism and said rocking .frame and said carrier, respectively, whereby said frame is rocked to direct the carrier to the opposite side of the needle-path and the carrier is advanced for engagement of its cutting and nipping elements with the thread leading from the needle-eye.

14:. In a buttonhole stitching machine, the combination with stitch-forming mechanism including a reciprocating needle, and slitcutting mechanism, of a thread-severing and nipping device comprising a rocking frame, a fulcrum therefor arranged transversely to the needle-path, a carrier sustained by said rocking frame and movable thereon in substantially the plane of said fulcrum, pairs of separable cutting and nipping elements mounted upon said carrier and sustained normally at one side of andretracted from the needle-path, a permanent connection be tween the slit-cutting mechanism and said rocking frame whereby the carrier is directed toward the opposite side of the needlepath, and a'normally disconnected connection between the slit-cutting mechanism and the carrier whereby the latter is actuated after the shifting of the rocking frame to advance its thread-cutting'and nipping elements into operative relation with the stitch-forming mechanism.

15. "In a buttonhole stitching machine, the combination with stitch-forming mechanism including a reciprocating needle, and slitcutting mechanism including a reciprocating member, of a thread-severing and nipping device comprising a rocking frame, a fulcrum therefor arranged transversely to the needle-path, a carrier sustained by said rocking frame and movable thereon in substantially the plane of said fulcrum, a cam-arm operatively connected with said carrier, cutting and nipping elements mounted upon said carrier and sustained normally at one side of and retracted from the needle-path, a permanent connection between the slitcutting mechanism and said rocking frame for rocking the latter upon its fulcrum, and a stud-pin mounted upon said reciprocating member of the slit-cutting mechanism and adapted for engagement with said camarm for imparting operative movements to said carrier.

16, In a buttonhole stitching machine, the combination with stitch forming mechanism, of a carrier normally retracted to one side of the path of said stitch-forming mechanism, a cam-block mounted at the other side of said path, thread-cutting means sustained by said carrier and comprising a fixed member and a movable member coacting therewith, and means intermittently engaging thecarrier to positively move the same across the path of said stitch-forming mechanism, whereby said movable cutting member is brought into direct engagement with said cam-block and is actuated thereby to sever the thread of said stitch-forming mechanlsm.

17. In a buttonhole stitching machine, the

combination with stitch-forming mechanism, and a worleholder, including a clamping device, of a tln'ead-severing device including a carrier supported independently of the workholder and sustaining the fixed member of a shear-cutter, means for sustaining said carrier for endwise movement toward and from the work-holder, a spring-pressed cutterlever fulcrumed upon said carrier, a movable shear-cutter member carried by said cutterlever in operative relation with the fixed cutter-member, a cam-member sustained by the work-holder within the path of movement of said cutter-lever, means for imparting operative movements to said carrier to effect-the engagement of the cutter-lever with said cam-member and means whereby the cam-member may be retracted out of the path of said cutter-lever as the latter returns from the work-holder. v

1-8. In a buttonhole stitching machine, the

combination with stitch-forming mechanism, and a work-clamp, of a movable carrier mounted independently of said clamp and normally retracted therefrom, thread-cutting means sustained by said carrier and comprising a fixed cutter member and a movable'cutter member coaeting therewith, a

cam-block sustained by said work-clamp,

and means for operating said carrier whereby' the movable cutter member is brought into engagement with, and is actuated by,

said cam-block, to sever the thread of said stitch-t'ormin; mechanism.

l9. Ina buttonhole stitching machine, the combination with stitch-forming mechanism, and awork-clamp, of a thread-severing device including a carrier mounted independently of said clamp and sustaining a fixed cutter member and a movable cutter member coacting-therewith, a lateral stud carried by said movablecutter member, a cam-block pivotally mounted upon the work-clamp and provided with a cam-lip having operative faces within and inclined to the path of movement of said "tud upon the movable cutter mem her, and means for imparting operative movements to said carrier to effect the engagement of said stud with said cam-lip of the pivotal] y mounted cam-block.

20. In a but-tonhole stitching machine, the combination with stitch-forming mechanism, and a work-holder, of a thread-severing device including a carrier sustaining the fixed member of a shear-cutter, means for sustaining said carrier for endwise movement toward and from the work-holder, a springpressed cutter-lever fulcrumed upon said carrier and provided with a. lateral stud, amovableshear-cutter member earried by said cutter-lever in operative relation with theffi -Xedjoutter member, a cam-block pivotally mounted upon thework-holder and provided with a'cam-lip having operative faces within and inclined to the path of movement of said stud upon the cutter-lever, and means for imparting operative movements to said carrier to effect the engagement of said stud with said cam-lip of the pivotally mounted cam-block, whereby the cutter-1ever maybe turned upon its fulcrum during the movement at the carrier toward the -\\-'ork-holder and the cam-block may be turned ioutof the path of the carrier as the sameis. retracted from the work-holder.

In testimony whereof, we have signed our names to this specification, in the presence of two subscribing witnesses.

JAMES o. GREnNE. LOUIS F. A. BUCHNER. Vitnesses HENRY J. IVIILLER,

HENRY A. konNnMANN, Jr.

Correction in Letters Patent No. 1,208,949.

It is hereby certified that in Letters Patent No. 1,208,949, granted December 19, 1916, upon the application of James G. Greene and Louie F. A. Bflchner, of

Elizabeth, New Jersey, for an improvement in Thread-Cutting Devices," an error appears in the printed specification requiring correction as follows: Page 4, lines 3031, c]nim 4, for the word "seberably" read separately; and that the said Letters Patent should be read with this correction therein that the same may conform I to the record of the case in the Patent Office.

Signed and sealed this 30th day of January, A. D., 1917.

F. \V. H. CLAY.

Acting Commint'amr of Patents.

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